This disclosure relates to sensors for autonomous or highly automated vehicles and specifically the calibration thereof. Some vehicles are configured to operate autonomously, with no or very little input required by the driver. Instead, vehicle systems are controlled by a computing device associated with the vehicle, using information about the vehicle's movement and the surrounding driving environment captured by various sensors (such as cameras) disposed on or otherwise affixed to various points on the vehicle. Over time, these sensors can move out of alignment and may need to be recalibrated. If left uncalibrated, the reliability of the information obtained by the computing device from the sensors can be negatively affected.
One method of calibrating a camera involves displaying an object with a predefined geometry at a known position relative to the camera. Because the geometry of the object is known in advance, a computer controlling the camera can compensate for variations between the object as observed and the known actual dimensions of the object. Thus the camera is calibrated. One way of ensuring a consistent geometry on the object is to use a panel patterned with a predefined pattern having known dimensions. Checkerboard patterns are commonly used for this purpose.
One challenge with this method of visual calibration is that one must ensure that the calibration object must placed in the predefined position accurately and with substantial precision. This can require expertise and experience in robotics and mathematics, and is likely out of the reach of ordinary consumers. Therefore, with respect to an autonomous passenger vehicle, a driver will require professional assistance and will have to bring the vehicle to the dealership in order to have the vehicle's sensors calibrated.